The man, thought to be a German tourist, had a face mask but kept taking it off, ignoring the pleas of staff and fellow passengers on the vaporetto, local media reported on Monday.
He was forcibly removed from the boat after repeatedly refusing to wear his face mask and mocking crew and passengers who asked him to abide by the rules.
The man then tried to board again but passengers blocked his path, with one enraged man needing to be restrained in his efforts to ensure the tourist didn’t set foot on board.
The boat eventually left the man behind on the pier.
The incident came after a group of young adults in Rome mocked police who asked them to wear face masks, with those who refused to comply with the rules handed a €400 fine.
Under Italian rules aimed at curbing the spread of coronavirus, face masks must be worn on public transport and in public indoor spaces at all times.
They are also mandatory in busy or crowded outdoor areas between 6:00 pm and 6:00 am.
The only exceptions are for children under six or people with a health condition that makes it impossible.
The rules on mask-wearing were tightened in mid-August as the number of new positive cases in Italy began to rise again.
They will apply until at least September 7, when the government will decide whether to extend them further.
Video: Corriere della Sera
